Steel in Façades: Strength, Durability, and Architectural Expression
In the field of exterior cladding, steel is an essential material. Denser and stronger than aluminum, it is perfectly suited for projects requiring high mechanical strength, a strong visual presence, and long-term structural stability. Far from being limited to industrial contexts, steel today is used in a wide variety of architectural applications, from institutional buildings to public infrastructure, commercial developments, and cultural facilities.
At Cyrell AMP, we support professionals in selecting the right type of steel, the most suitable surface treatment, and the correct assembly details, taking into account the exposure environment, aesthetic objectives, and durability requirements.
A High-Performance Material
One of steel’s major advantages is its resistance to deformation, tensile forces, and impact. It is particularly well suited to areas subject to frequent stress: building bases, pedestrian-level walls, public spaces, or industrial sites. Unlike aluminum, steel generally requires corrosion protection, except for specific types such as stainless or corten steel. Fortunately, modern treatment solutions allow this requirement to be addressed effectively.
The Main Steel Options for Façades
1. Pre-Painted Steel
Pre-painted steel is galvanized steel coated in a continuous process at the factory using coil coating technology. This industrial process ensures a uniform finish, excellent batch-to-batch color consistency, and long-term chromatic stability. It is a cost-effective, fast-to-install solution, ideal for continuous façades, decorative panels, or large-scale projects where meeting budget and schedule requirements is critical.
However, pre-painted steel is typically available in a standardized palette, generally limited to a few common architectural shades. For projects requiring custom colors, special finishes can be produced, but usually only for orders above a threshold of around 25,000 sq. ft. due to production constraints.
In terms of durability, its resistance to scratches, impacts, and corrosive agents is lower than that of powder-coated aluminum. For this reason, it is best used on higher or less exposed surfaces to preserve the integrity of the finish over time.
2. Stainless Steel (304 and 316)
Stainless steel is a premium solution for projects requiring extreme durability, particularly in aggressive environments such as coastal areas, polluted urban zones, or heavy industrial locations. Grade 304 is suitable for most exterior applications, while grade 316—with added molybdenum—is recommended for more corrosive contexts, such as marine locations, areas exposed to de-icing salts, or near chemical plants, due to its superior chloride resistance.
Valued for its high-end appearance, stainless steel offers a noble finish—often satin or brushed—and excellent dimensional stability. It lends façades a refined, technical, and timeless character, highly sought after in institutional and prestigious architectural projects.
However, stainless steel does come with considerations. It is sensitive to micro-scratches and to fingerprints or grease marks, especially on polished surfaces, which may require more frequent maintenance in accessible areas. It is also significantly heavier than aluminum or galvanized steel, which can have a considerable impact on the load-bearing structure, handling on site, and transportation or installation costs. This higher density requires careful evaluation during the design phase, particularly for large formats or systems installed at height.
3. Corten Steel
Corten steel is prized for its raw, evolving appearance. Over time, it develops a protective rust-colored patina, ranging from brown to orange, which acts as a barrier against corrosion. This patina forms naturally under alternating wet and dry conditions, without the need for additional coating. It enhances durability while giving the material a unique, ever-changing character.
Widely used in cultural, institutional, landscape, and urban design projects, corten offers an expressive, organic aesthetic that integrates seamlessly with its surroundings. It is often selected to highlight materiality and enhance the visual impact of architecture.
The patination process can be adjusted to project needs. For accelerated oxidation and faster achievement of the desired look, some manufacturers apply chemical treatments in the factory or workshop. Conversely, it is also possible to stabilize the surface at a given stage using a clear varnish or fixative. This approach halts the visual evolution of the patina and limits rust runoff—a particularly useful measure near light-colored or sensitive surfaces.
Corten installation requires careful detailing. Adequate drainage is essential to prevent water stagnation, and protection of adjacent materials is necessary—particularly at the base of façades or near paved surfaces—to avoid staining during active oxidation phases.
Steel or Aluminum? Two Complementary Materials
Steel does not replace aluminum—it complements it. While aluminum stands out for its lightness and malleability, steel offers visual density, increased rigidity, and exceptional durability under the right conditions. The choice between the two materials depends on the exposure environment, budget, desired aesthetic, and the location of the cladding on the building (base or upper levels).
Beware of Mixing Metals: Galvanic Corrosion
When different metals are used in the same building envelope—such as aluminum panels with steel structural or fastening elements—the risk of galvanic corrosion must be carefully considered. This occurs when a less noble metal (like aluminum) is in direct contact with a more noble one (such as stainless or even galvanized steel) in the presence of an electrolyte (rain, condensation, melted snow, etc.).
The less noble metal then degrades more quickly. In a façade, this can lead to pitting corrosion, staining, or premature coating failure.
To prevent this:
- Electrically isolate metals with nylon washers, dielectric tape, or non-conductive fasteners
- Use properly sized sealants to prevent stagnant water between metals
- Choose compatible fastening systems (e.g., stainless screws for aluminum, with insulating washers)
- Avoid water accumulation or cross-runoff between incompatible materials
In short, aluminum and steel can coexist perfectly—provided the junctions are designed with care. Understanding galvanic corrosion is essential to ensuring long-term durability of the cladding system.
Conclusion
Robust, versatile, and undeniably architectural, steel offers numerous possibilities for exterior cladding. While it requires particular attention to corrosion protection and surface finishing, it compensates with its longevity, mechanical strength, and aesthetic richness. At Cyrell AMP, we bring our expertise to help you choose the right grade, treatment, and installation details according to your project’s real-world demands.